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A249876
Pseudo-lucky numbers.
4
1, 3, 5, 7, 11, 13, 17, 21, 23, 25, 31, 35, 41, 43, 45, 47, 55, 57, 63, 65, 73, 75, 83, 87, 95, 97, 101, 105, 107, 113, 123, 127, 131, 133, 141, 143, 147, 151, 153, 161, 175, 177, 183, 185, 197, 201, 211, 213, 215, 217, 227, 233, 235, 237, 251, 255, 265, 267
OFFSET
1,2
COMMENTS
Appears to grow more slowly than the Lucky numbers. - Jon Perry, Nov 07 2014
LINKS
Jean-François Alcover, Table of n, a(n) for n = 1..1000
EXAMPLE
Start with the natural numbers. The 2nd number is 2, so delete every 2nd number, leaving 1 3 5 7 9 11 13 15 17 19...; the 3rd number remaining is 5, so delete every 5th number, leaving 1 3 5 7 11 13 15 17 ...; now delete every 7th number, leaving 1 3 5 7 11 13 17 ...; now delete every 11th number; etc.
MAPLE
L:= [seq(i, i=1..10^3)]:
for n from 2 while n < nops(L) do
r:= L[n];
L:= subsop(seq(r*i=NULL, i=1..nops(L)/r), L);
od:
L;
MATHEMATICA
FixedPoint[Function[{L}, n++; Delete[L, List /@ (L[[n]]*Range[Quotient[Length[L], L[[n]] ]])]], n=1; Range[1000]] (* Jean-François Alcover, Nov 27 2014 *)
PROG
(Python)
def listed(n):
L=list(range(1, n+1)); j=1
while L[j] <= len(L):
L=[L[i] for i in range(len(L)) if (i+1)%L[j]!=0]
j+=1
return(L)
CROSSREFS
Cf. A000959 (Lucky numbers).
Sequence in context: A062280 A069467 A309739 * A096169 A225526 A090670
KEYWORD
nonn
AUTHOR
Robert FERREOL, Nov 07 2014
STATUS
approved